Slice the top of pineapple and the bottom off. Stand the pineapple on its side and with a sharp knife, slice sides of pineapple off. Cut the pineapple into small slices and then remove the core of each slice. (The core tends to be hard to eat, but I’ve had some pineapples were it was soft). Dice the remaining pineapple into small pieces.
Toss all of the ingredients into a bowl and chill for a couple of hours to let the flavors marinate.
Season each side of the fish with garlic powder, fresh ground pepper and sea salt.
Heat grill to medium high heat. Grill each side for about 4-5 minutes, until inside of the fish is a nice medium rare. Top with pineapple salsa! Enjoy!